Method of and device for producing sound band matrices



A. WOITS CHECK METHOD OF AND DEVICE FOR PRODUCING SOUND BAND MATRICES Y7 Sept. 25, 1945.

Filed May 26, 1941 Wren/o2."

Patented Sept. 25,

METHOD OF AND DEVICE FOR PRODUCING SOUND BAND MATRICES Arno Woitscheck,Porz, near Cologne, Germany; vested in the Alien Property CustodianApplication May ale-1941, Serial No. 395,317 In Germany May 22, 1940 4Claims.

It is known to produce sound band matrices galvanoplastically. For thispurpose, it has been proposed 'to (provide an original sound bandbearing the sound record, for exam'ple a wax band, with an electricallyconductive surface and then to place it in a galvanic bath, in which acopper deposit is produced on the recorded side of the band, whichcopper deposit, after having been separated from the original soundband, represents the matrix.

This manner of producing pressing or stamping matrices has thedisadvantage of taking up much time and being rather expensive,particularly when it is the question of producin broad sound bandmatrices with a number of sound tracks running at the sides of eachother. It requires a comparatively long time until the matrix hasacquired the necessary thickness in the galvanic bath.

Further disadvantages of the method described are that, owing to theabsolutely necessary current connection at the conductive surface of theoriginal sound band, the galvanically produced matrix will always benarrower than the original sound band, and that the edges of the matrixare not smooth, and hence both edges of the matrix later have to be cutstraight. This still more reduces the already smaller width of thematrix and, therefore, it is necessary from the beginning to make thematrix in the galvanic bath considerably wider. Moreover, galvanicallyproduced sound band matrices of copper are too soft for the productionof large numbers of duplicates of sound bands in a pressing or stampingoperation, and it is not at all desirable to use the original matrix forpressing or. stamping operations, because, if this matrix is dainaged orspoiled, the original record is no longer available. Therefore, it isnecessary to use the original matrix for first making a patrix fromwhich one or several pressure-resisting matrices are produced for thepressing or stamping operation. The patrix is produced in a galvanicbath, the original matrix serving as a cathode. The result of this isthat, for the reasons given above, the width of the patrix will be stillsmaller than the already considerably reduced width of the originalmatrix. The same disadvantage occurs when the matrix, intended to servefor the pressing or stamping operation, is produced from the patrix. Inorder to obtain a pressing matrix corresponding to the-normal width ofthe sound band suitable for reproduction, it is, therefore, necessary toproduce an original matrix the width of which is half as wide again asthe pressing matrix.

The object of the invention is to obviate these as well as otherdisadvantages of the known method. This is achieved, in the first place,by producing the matrix or patrix band in the galvanic bath so as tohave a width only slightly exceeding the width of the sound track bundleand a thickness amounting to merely a fraction of the requiredthickness, the band obtained in this manner-4f necessary, after havingits edges worked-being inserted in an unrecorded wider metal band theedge portions of which have the desired thickness of the matrix orpatrix, and the central portion of which is provided with an openingcorresponding to the cross section of the in the manufacture ofgramophone records consisting in soldering a very thin disc-shapedpressing or stamping matrix, with a thickness of only a few tenths of amillimeter, onto a thick metal plate, in order to protect the matrixagainst certain influences .of the plate material employed, as well asagainst careless handling by the operator.

The method is advantageously carried out in a manner in which the matrixor patrix band is produced in the galvanic bath so as to have athickness equal to one half of that required, in

a width but slightly exceeding the width of the sound track portion, theband obtained in this way being fixed to the central portion of a wider,

unrecorded metal band of equal thickness, the.

free edge portions of this metal band being folded round until theiredges touch those of the recorded hand.

For making pressing or stamping matrices for the production of verylarge numbers of sound bands, the invention provides that an originalmatrix is inserted'in a widening band of the type described, therecorded side of the composed band obtained in this manner being coatedwith an,

oxide layer, whereupon a patrix having a width equal to that of thetotal band is produced in a. galvanic bath, said patrix-if necessary,after its edges have been worked-being inserted in another wideningband, the composite band obtained in this manner being coated with anoxide layer, and, finally, a thick nickeled and chromed pressing orstamping matrix being produced from the composite patrix band in agalvanic bath.

Advantageously, the narrow recorded matrix or patrix band iscontinuously Ied'to a uniformly moved, heated widening band, at the sametime applying to its recorded side a protective coating preventing itfrom tarnishing, and its back being coated with a soldering paste, bothbands being pressed together from the place where they first comeintocontact with each other. This part of the method is preferablycarried out by means of an arrangement which is provided with a devicefor continuously folding the edge portions of a uniformly moved,unrecorded band, a device for uniformly feeding and inserting the narrowrecorded matrix or patrix band in the channel formed by the folded edgeportions of the unrecorded band, a heating ,device for the unrecordedband disposed between the folding device and the place where therecorded band is fed in, and a device for pressing together the twocombined hands behind the f ceding-in place. The device for feeding" therecorded band may be provided with elements serving to apply aprotective paste to the recorded sideof the band, and with elements forapplying soldering flux to the back of the band. The device for pressingthe bands together behind the feeding-in place of the recorded bandadvantageously consists of individual spring-controlled rollers.

The method forming the subject of the invention is diagrammaticallyillustrated in the accompanying drawing which also contains a die.-

grammatical illustration of a device of the type' described.

Fig. 1 shows a plan view and a section of a' piece of a recordedoriginal sound band;

' Fig. 2 is a plan view and a section of the original matrix producedfrom the sound band according to Fig. 1 after the original sound bandhas been separated; and

Fig. 3 also shows a plan view and a section of the trimmed originalmatrix.

Fig. 4.is a plan view and a section of a piece of a widening band; and

Fig. 5 is a plan view and a section of the widen ing band according toFig. 4 with the insertedoriginal matrix according to Fig. 3 and Fig. 6illustrates the device for inserting the original matrix in the wideningband and for producing the latter.

The original sound band, for example, consists of a. nitrocellulose bandI coated with a wax layer 2 into which are cut the sound grooves 3.After having been recorded, the band is coated with graphite, or itsrecorded side is provided with some other conductive coating. Thereuponthe band is placed in a galvanic bath, the conductive coating of itsrecorded side being connected to the source of current of the bath. Forthis purpose, there are provided the indicated clamping devices 4 whichpass beyond the edge of the conductive surface layer.

The copper deposit, which is now produced in the galvanic bath, forms amatrix between the clamping devices 4 on the graphite-coated surface ofthe original sound band, the deposit-- forming operation being continueduntil the thickness of the matrix has reached one half of i thethickness required. Then, the matrix is drawn has already lostconsiderably in width as compared with the width of the wax layer of theoriginal sound band. Its width has been reduced by the galvanizingoperation as well as by the working of its edges as compared with thewaxlayer 2 of the carrier layer I of the original sound band. If thematrix according to Fig. 3 should be used to galvanically produce apatrix. and if a matrix would be made of this patrix, the width of thelast mentioned matrix would be coniderably smaller than that of theoriginal matrix.

In order to compensate for the loss of width, the invention provides forthe use of a widening band. A piece of such a band is illustrated inFig. 4. It consists of a smooth copper band 8, whose edge portions 9 arefolded over. The band 8 has the same thickness as the matrix Saccordingto Fig. 3 and, therefore, in its central portion 'has half thethickness, and in its edge portions the full thickness of the matrixband to be produced.

Now, the matrix 5 is inserted, with the sound record side out, in theopening formed by the folded edges 9 of the widening band 8, where uponthe back of the matrix is soldered on to the bottom of the opening. Thisis illustrated in Fig 5. By the one-piece connection a matrix band isproduced'which has the desired thickness and a considerably greaterwidth than the galvanically produced matrix band 5. Nevertheless, only apart of the entire matrix needs to be produced galvanically.

The composite matrix according to Fig, 5 is now provided on its recordedside with an oxide layer, for example by silvering the recorded side andsubsequently oxidizing the silver layer in a bath consisting of asolution of iodine and bromine in alcohol. Thereupon the matrix is againbrought into the galvanic bath and a patrix is produced therefrom,which, after having beenv cut at its edges, is also narrower than thematrix;-

In order to compensate for this loss in width, the patrix is inserted inthe manner described above in a widening band according to Fig. 4 and issoldered on to this band. The total patrix widv ened in this way isagain coated on its recorded side with an oxide layer and is broughtinto the galvanic bath, in which a matrix is produced therefrom. Thismatrix is then wide enough to be used for pressing or stamping soundbands. The pressing or stamping matrix is produced in the galvanic batheither in full thickness or in a fraction of this thickness, in whichcase it is attached to a band having the missing thickness of thematrix. Finally, the pressing matrix is nickeled and chromed and is thenready for use.

The inserting of the original matrix or of the patrix in the wideningband and the soldering lustrated at M, corresponding to that of Fig. 4.

having half the thickness sired for the side of the matrix band with acoating serving to preventthe sound tracks rrom tarnishing under theiniluenceoi the heat required for soldering together the bands I and I.The coating is water-soluble and is washed of! after the two bands havebeen soldered together. At 24 is indicated a device for coating the backof the matrix band with soldering flux.

The matrix band is inserted through the. rollers 2|, 22 in the openingof the widening band, and-behind the rollers 2|, 22 there are arrangedspringcontrolled individual rollers 25 above and below the two bands 5and 8, serving to press the matrix band, the back of which iscoated'iwith soldering paste, against the heated wideningwband. Afterhaving passed through the system of rollers 25, the bands 5 and 8 arerigidly connected with each other. The cross section or the combinedband system is illustrated at 26.

The device illustrated in Fig. 6 is used in a similar manner for patrixband in a widening band.

The invention is not limited to inserting a galvanically produced matrixor patrix band, of the matrix or patrix to be produced, in a wideningband the central portion of which has the same thickness as thegalvanically produced matrix or patrix band; as it is also possible togalvanically produce a matrix or patrix band whose thickness representsa difierent fraction of the total thickness required, and this band maybe inserted in a widening band whose edge portions have the requiredtotal thickness 01' the matrix or patrix, and whose central portion hasan opening, the depth of which is equal to the thickness or thegalvanically produced matrix 01' patrix band.

As both matrix and patrix bands may be made in this way, capable of usefor the production of either patrices or matrices (including the actualreproduction records themselves), the product is herein referred to as acomposite reproducing band having a duplicating portion and a wideningportion.

What is claimed is:

1. A method oi making widened composite reproducing bands for theproduction of sound record bands by means of a galvanoplastic deposit,which comprises preparing a duplicating band from an original recordband, said duplicating band having a width slightly greater than thewidth of the sound track portion oi the or- ,iginal record band and witha thickness less than the required thickness for the reproducing band tobe made, preparing a wider conductive band having edge portions of thethickness dereproducing band and having a inserting and connectingtli 3central portion with a longitudinal recess corresponding to thecross-section of the said duplicating band, and then securing theduplicating band in position in said recess with its upper surface inthe plane or the said edge portions.

2. A method of making widened composite reproducing bands for theproduction oi. sound record bands by means of a galvanoplastic deposit,which comprises preparing a duplicating band from an original recordband, said duplicating band having a width slightly greater than thewidth of the sound track portion or the original record and with athickness less than the required thickness for the reproducing band tobe made, turning the edges of a wide metal band over to provide edgeportions of the thickness desired for the reproducing band, whileleaving a gap between the edges of the original blank for providing alongitudinal recess corresponding to the cross-section oi the saidduplicating band, and

then securing the duplicating :band in position" in said recess with itsupper surface in the plane of the said edge portions.

3. A method of making producing bands for the production or sound recordbands by means 01' a galvanoplastic deposit, which comprises preparing aduplicating band from an original record band, said duplicating bandhaving a width slightly greater than the width of the sound trackportion of the original record band and with a thickness less than therequired thickness for the matrix or patrix tobe made, preparing a widerconductive band having edge portions of the thickness desired for theduplicating band and having a central portion with a longitudinal recesscorresponding to the cross-section of the said duplicating band,advancing the conductive band and heating it during its advancement,coating the duplicating band on its face with a protective coating andon its back with a solder paste while continuing to advance the same,advancing the duplicating band and bringing it face up into the recess01' the widening band while the latter is in heated condition, andpressing the hands together while continuing their advance at the samespeed.

4. A composite reproducing band of desired width and having a mechanicalsound record thereon, comprising a duplicating portion bearing the soundrecord, and a relatively wider band widened composite rehaving a centrallongitudinal recess of crosssection identical with thatoi' theduplicating portion, said portion and the wider band being securedfixedly together throughout their lengths and providing a flexiblearticle for preparing duplicates of thedesired width. 1

v r I ARNO WOITSCHECK.

